Closing this as there is no response from the reporter of this issue. The module works as expected. If the class exists in on the page the javascript adds the link and the copying function works.
As far as I can see this module behaves as expected with views. If otherwise, please let me know with details. Thank you.
As long as the displayed page contains the enclosing tag with the cp-to-clip class this should work.
While adding custom text to the header you would have to ensure that the tags are not stripped off, as is usually the case unless you specify that the text should be unfiltered.
For the views field: adding a Style settings -> Customize field HTML with a DIV -> Add HTML class cp-to-clip works; i.e. the copy button appears and text is copied.
A few more details to reproduce the situation might help.
If you rewrite a field to add the class "cp-to-clip" it works fine.
Please let me know how to reproduce your situation.
Thank you
phpcs is run and all issues are fixed.
The release is at
https://www.drupal.org/project/cp2clip/releases/1.0.1-rc1 →
composer require 'drupal/cp2clip:^1.0@RC'
The initial release is ready. You should be able to install it now. More details below: